Terraform

Free

Hashicorp Learn: Aws - Hashicorp's official getting started tutorial for AWS

Hashicorp Learn: Azure - Hashicorp's official getting started tutorial for Azure

Hashicorp Learn: GCP - Hashicorp's official getting started tutorial for GCP

Ned in the Cloud: Terraform Basics - A great playlist of videos covering the basics of Terraform

Awesome-TF - A curated list of Terraform resources

Paid

More than Certified: HashiCorp Terraform - a great course that also covers some fun projects with Docker, k3s, Node-Red IOT, and CICD deployments.